1. Geothermal Retrofit of HVAC Systems
Absorption Chiller
(Yazaki Energy Systems)
Water-water
plate heat exchanger
Water-air
heat exchanger
Andrew Chiasson
Geo-Heat Center
Oregon Institute of Technology

2. Retrofit Possibilities
Space heating
Domestic hot water
Suitability depends mainly on flow requirements and need for storage
Space cooling
Newer absorption chillers rated at 192oF

3. HVAC Systems Types Several types of configurations for space heating
HVAC systems are categorized by the method used to convey energy
All-air systems
Air-and-water systems
All-water systems

4. HVAC Systems All-Air Systems
All heating, cooling, and humidification is supplied to a space by the air
Single-duct systems
Constant volume
Multi-zone, variable-air volume (VAV)
Multi-zone with re-heat
Dual-duct systems

5. HVAC Systems All-Air Systems
Single duct systems
Fossil-fuel furnace with direct-expansion (DX) cooling

6. HVAC Systems All-Air Systems
Single duct systems
Commercial system with central heating and cooling coils

7. HVAC Systems All-Air Systems
Single duct systems
Commercial roof-top units

8. HVAC Systems All-Air Systems
Single duct systems
Commercial system with central heating and cooling coils

9. HVAC Systems All-Air Systems
Single duct systems
Multi-zone commercial system with variable-air volume (VAV) fan

10. HVAC Systems All-Air Systems
Geothermal Retrofit Suitability (Rafferty, 1998)
Low Temperature water (<150oF)
Single-zone, multi-zone, dual duct 8-10
Terminal reheat, VAV
Standard Temperature water ( oF)
Single-zone, multi-zone, dual duct 7-8
Terminal reheat, VAV
Steam
Single-zone, multi-zone, dual duct 6
Terminal reheat, VAV
Electric resistance furnace 5-6
Air-air split heat pump
Fossil-fuel furnace
Packaged roof-top unit
Fossil-fuel fired unit heaters 3-4

11. HVAC Systems All-Water Systems
Hot and chilled water are distributed to terminal units and equipment
Free-standing radiators
Baseboard radiators
Wall, floor, ceiling panels
Fan coil units

12. HVAC Systems All-Water Systems
Fan coil unit
Unit ventilator (4-pipe)

13. HVAC Systems All-Water Systems
Fin tube radiator
Cast iron radiator

14. HVAC Systems All-Water Systems
Water loop heat pump (California loop)

15. HVAC Systems All-Water Systems
Geothermal Retrofit Suitability (Rafferty, 1998)
Loop heat pump
Radiant panel
Fan coil/unit ventilator
Unit heaters
Finned tube convector 6
Steam systems

16. HVAC Systems Perimeter Electric Systems
Geothermal Retrofit Suitability (Rafferty, 1998)
Electric baseboard 2
Through-the-wall units 1